MacNN posted a link to this Sorenson vs. MPEG-4 shootout by Jeremy Neish.
Neish writes: My original goal for conducting this shoot-out was to prove to myself and to the world that QuickTime with the Sorensen codec is the best solution for mid to low datarate video. As it turns out - I was wrong.
Looks like MPEG-4 wins in Quality and Speed of Compression, and loses on Compatability and Data Rate Accuracy.
Note: There is a break in the pages, where there is no link to go on. You can pick back up with this link.